Nitrile metabolism in fungi: A review of its key enzymes nitrilases with focus on their biotechnological impact

Publication date: Available online 14 January 2019Source: Fungal Biology ReviewsAuthor(s): Ludmila MartínkováAbstractNitriles are abundant in the plant kingdom. The ability to detoxify them is beneficial for microbes living in the plant environment. Nitrilases (NLases; EC 3.5.5.-), which hydrolyze nitriles to carboxylic acids, have been well characterized in bacteria, and classified into various substrate-specificity subtypes (aromatic NLases, aliphatic NLases, arylacetoNLases). NLases also occur in filamentous fungi, mainly in Ascomycota (subdivision Pezizomycotina), as documented by genome mining. However, the investigation of NLases in fungi has been delayed compared to bacteria. Only a few NLases (aromatic NLases) were purified from native fungal strains (mainly Fusarium), which were grown under suitable induction conditions. Over a few past years, the spectrum of known fungal NLases was broadened by expressing fungal NLase genes in Escherichia coli. Thus functional NLases were reported for the first time in fungi of genera Auricularia, Macrophomina, Nectria, Neurospora, Pichia, Talaromyces, Trichoderma and Trichophyton. Two major substrate-specificity subtypes were identified in them, i.e. aromatic NLases and arylacetoNLases, apart from a few NLases with broad substrate specificities. The biotechnological impact of fungal arylacetoNLases was explored with a focus on the enantioselective hydrolysis of (R,S)-mandelonitrile, the selective hydrolysis of one cyano group in ...
Source: Fungal Biology Reviews - Category: Biology Source Type: research